The Food Standards Agency (FSA) said its revised advice that those vulnerable to infection could now safely eat raw or lightly cooked eggs produced under the British Lion Code of Practice followed a thorough review of new scientific evidence.

It had previously advised that vulnerable groups should not eat runny eggs because they could contain salmonella bacteria which can cause serious illness.

A report published by the Advisory Committee on the Microbiological Safety of Food (ACMSF) in July last year said the presence of salmonella in UK eggs had been “dramatically reduced” in recent years, and the risks were “very low” for eggs which had been produced according to the British Lion code.

More than 90 per cent of UK eggs are produced under this scheme.

FSA chairman Heather Hancock said: “It's good news that now even vulnerable groups can safely eat UK eggs without needing to hard-boil them, so long as they bear the British Lion mark.

“The FSA has thoroughly reviewed the scientific evidence about the safety of these eggs, and we're confident that we can now change our advice to consumers.

“The major reduction in the risk of salmonella in Lion eggs is testament to the work carried out by egg producers. The measures they've taken, from vaccination of hens through to improving hygiene on farms and better transportation, have dramatically reduced salmonella levels in UK hens.”

The revised advice does not apply to severely immunocompromised individuals who need medically supervised diets prescribed by health professionals.

The existing advice on UK eggs that do not carry the Lion mark, non-hen eggs and eggs from outside the UK is that they should always be cooked thoroughly for vulnerable people.

Fears over salmonella peaked in the late 1980s when two million chickens were slaughtered and pregnant women were told to avoid undercooked eggs.

In 1988 Edwina Currie, then a junior health minister, said most egg production in Britain was infected with salmonella. Her comments sparked a public outcry and two weeks later she was forced to resign.

By early 1989 the link between eggs and salmonella poisoning was proved beyond doubt.